The goal of the proposed research is to understand the roles of centrifugal input in vertebrate retinas. In all vertebrates (include humans), the retinas receive centrifugal input from the brain. In fish, the centrifugal input originates from the terminalis nerve (TN) in the olfactory bulb. In the retina, the TN fibers synapse onto dopaminergic interplexiform cells (DA-IPCs). The proposed research will investigate the biological roles of the centrifugal pathway in visual system functions. Specifically, we will determine the physiological properties of the TN cells, the effects of centrifugal input in vision, and the genetic mechanisms of the development of the centrifugal pathway. The results from the proposed research will shed light on the mechanisms of centrifugal modulation of visual sensitivity.